孔隙比对土体动力特性参数的影响-以豫东平原粉土为例

孔隙比是粉土重要的物性参数,影响着粉土的动力特性参数,进而影响到粉土场地的动力稳定性评价.为分析豫东平原粉土孔隙比对动力特性参数的影响规律,利用固定自由型共振柱测试仪,对取自豫东平原地区的粉土进行重塑共振柱试验,研究不同固结压力下粉土孔隙比对动剪切模量和阻尼比的影响.研究发现:不同孔隙比粉土动剪切模量随动剪应变的增大存在相同的衰减趋势,不同孔隙比粉土阻尼比随动剪应变的增大存在相同的增长趋势;固结围压一定时,粉土动力特性参数随孔隙比的增大而降低;在相同试验条件下,小孔隙比粉土的最大动剪切模量大于大孔隙比粉土的最大动剪切模量;用线性函数能较好地拟合粉土最大动剪切模量与孔隙比之间的关系.研究提出了适用于豫东平原粉土的动剪切模量比和阻尼比拟合函数及参数值,为粉土场地动力稳定性评价提供依据.

Effect of Void Ratio on Soil Dynamic Characteristic Parameters:A Case Study of Silt in Eastern Henan Plain

Void ratio was an important physical parameter of silt, which affects the dynamic characteristic parametersand then affects dynamic stability evaluation of silt site. In order to analyze influence of void ratio on dynamic characteristic parameters of silt in Eastern Henan Plain, the influence of void ratio on dynamic shear modulus and damping ratio were studied by using fixed free-form resonance column tester. It was found that dynamic shear modulus of silt has the same attenuation trend with increase of dynamic shear strain. With the increase of dynamic shear strain, the damping ratio of silt with different void ratio has the same increasing trend. When consolidation pressure was fixed, the dynamic characteristic parameters of silt decrease with increase of void ratio. Under the same test conditions, the maximum dynamic shear modulus ofsilt small void ratio was larger than large void ratio. The relationship between maximum dynamic shear modulus and void ratio of silt could be well fitted by linear function. Dynamic shear modulus ratio fitting function, damping ratio fitting function and parameter value of silt in Eastern Henan Plain were proposed, which can provide basis for dynamic stability evaluatingof silt site.